Technical Field
Embodiments described herein relate to an energy management system, and more particularly, to a method for transferring data between an energy management system and multiple servers.
Description of the Related Art
With development of computer and communication technologies, the power system is now operated in the form of an energy management system (EMS)/supervisory control and data acquisition (SCADA), which is a distributed system. Thereby, production, transfer and distribution of power are effectively implemented.
However, as the language, operating system and communication protocol for the systems differ from one system to another, the systems suffer difficulties in exchanging data therebetween.
To address this problem, the US Electric Power Research Institute has announced a new communication protocol called Inter-Control Center Protocol (ICCP) to manage communications between power control centers. The ICCP has designated Manufacturing Message Specification (MMS), which is a standard communication protocol for automation, as a sub-protocol of the application layer to support smooth communication between different kinds of control centers.
Meanwhile, a next-generation EMS transfers ICCP data determined according to an agreed protocol to other servers.
Herein, the transferred ICCP data may be broadly divided into analog data and digital data. The analog data may include power generation amount data (of a generator level, substation level, area level, and the like), result data about computation of EMS-SCADA programs, EMS-power application result data, and logic status data (including a manual value, flag setting, tag setting, prohibition of scan, and the like) of a point changed by the EMS. The digital data may include physical status data (On/Off) about apparatuses and system status data (Active/Backup of the servers of the EMS).
The data transferred from the EMS may be received by one or more servers. The servers obtain and process necessary data through operative connection therebetween.
FIG. 1 is a block diagram illustrating a power system according to the prior art.
Referring to FIG. 1, the power system includes an EMS 10, server 1 20, server 2 30 and server 3 40.
Hereinafter, a description will be given of a data transfer procedure for the power system configured as above.
First, the EMS 10 is connected to server 1 20 in a one-to-one relationship. Thereby, the EMS 10 transfers data needed by server 1 20 to server 1 20 (step 1).
Subsequently, once transfer of the data to server 1 20 is completed, the EMS 10 receives reception result information (an acknowledgement (ACK) signal) from server 1 20 in response to transfer of the data (step 2). That is, the EMS 10 is connected with multiple servers in the one-to-one relationship, and thus transmits data to each connected server. Once transfer of data is completed with the EMS 10 connected with server 1 20 as described above, the EMS 10 needs to terminate connection to server 1 20 to establish connection to the next server for communication and transfer data. However, if server 1 20 fails to normally receive the data transferred by the EMS 10, the EMS 10 needs to perform the procedure of connection and transfer of data to server 1 20 again.
Accordingly, the EMS 10 receives reception result information indicating whether server 1 20 has normally received data.
Upon normally receiving the reception result information, the EMS 10 releases connection to server 1 20, and establishes one-to-one connection to server 2 30. Then, the EMS 10 transfers data to server 2 30 connected thereto (step 3).
Subsequently, once transfer of the data to server 2 30 is completed, the EMS 10 receives, from server 2 30, reception result information (an ACK signal) according to transfer of the data (step 4).
Then, upon normally receiving the reception result information, the EMS 10 releases connection to server 2 30, and establishes one-to-one connection to server 3 40. Then, the EMS 10 transfers data to server 3 40 connected thereto (step 5).
Subsequently, once transfer of the data to server 3 40 is completed, the EMS 10 receives, from server 3 40, reception result information (an ACK signal) according to transfer of the data (step 6).
Upon normally receiving the reception result information from server 3 40, the EMS 10 terminates the data transfer operation.
As described above, the EMS 10 transfers data to a server configured to receive the data by establishing one-to-one connection with the server. In the data transfer procedure, three steps of connecting to a server, transferring data and receiving reception result information needed to be performed to transfer the data to the server.
Accordingly, in order for the EMS 10 to transfer data to multiple servers, the aforementioned three steps need to be repeated by the number of the servers, and a corresponding code needs to be created.
Since the conventional EMS 10 needs to continue to perform the three steps to transfer data to multiple servers, time taken to transfer data may increase according to the number of the servers.
In addition, to switch from a server designated to receive data to another server, a created code needs to be modified. Thereby, recompiling is needed. To proceed with the process after the compiling, the process needs to be suspended for a certain time.
In addition, according to the conventional technology described above, it is not easy to add a server to receive data or remove a server.